The Internet allows for the easy exchange of electronic files. Sometimes, however, it is necessary for two parties engaged in exchanging files to verify that the files they are about to receive contain the information they desire. This situation is usually resolved by the use of an escrow agent. An escrow agent is a neutral third party that is trusted by both parties. The escrow agent receives the electronic file from the sending party and only transfers it to the receiving party once payment has been received by the sending party. However, this type of escrow arrangement is only successful if the agent is able to verify the authenticity of the electronic file.
Consider the following example: Party A wants to buy an MP3 file from Party B. If Party A pays Party B up front, Party A has no guarantee that Party B will send the MP3 file. If, on the other hand, Party B sends Party A the file before receiving payment, Party A has no incentive to pay, because he already has the MP3 file.
In the MP3 example, say Party A is buying “Yellow Submarine” by the Beatles. Unless the escrow agent can confirm that the song they received is indeed “Yellow Submarine”, the escrow transaction is useless. In most cases, such a verification of the transferred file is hard to do automatically, especially if its content is only relevant to the two transacting parties. In other words, sometimes the escrow agent cannot verify that the receiving party is getting what they are supposed to get.
The solution to this problem is to let the receiving party verify the asset. In the MP3 example, if the receiving party could listen to the MP3 file, they could confirm that it is what they wanted. As mentioned above though, if the receiving party got the entire file up front, they would have no incentive to pay.
The solution would be for the escrow agent to send the receiving party random portions of the MP3 file that they can listen to, e.g. most of the file is static, but random portions of it are left unaltered so you can hear the original. It is important that the various original portions of the song are in random places, so that the sending party can't simply send a file that contains mostly static to begin with. These random parts are chosen only once in the beginning of the transaction, because if they were to be re-selected randomly on separate occasions it may be possible for the receiving party to reconstitute the entire file simply by accessing it repeatedly, and thus obtaining a new small portion of it every time.
In another example, when two parties to a transaction sign a contract they may both want to have confirmation that the contract was also signed by the other party. The proposed method and system allows the parties to the transaction to upload an electronic version of the signed contract to a centralized server where neither party has access to the other party's file. However, both parties may review partial information about the file which is sufficient to confirm that the contract was indeed signed by the other party. Once both parties agree that the electronic document is as expected, the server releases the files to both parties.
In a different example, two individual members of an online dating site may want to exchange photos, but both parties are uncomfortable sending a photo to the other party before being certain they will receive the other party's photo. The system of the present invention allows both parties to upload their respective photos to a centralized, independent server, where they can both review small random portions of the photo to confirm that it is indeed a clear photograph of a person. Once both parties are satisfied and indicate so to the system, each can view the complete version of the other party's photo.